Calico Jack
Active Member
Your R&D unit is sandwiched between two flanges. One on the gearbox output shaft and one on the propshaft ?
Its purpose is to introduce a small amount of flexibility to the joint. However, it also electrically insulates the prop shaft from the gearbox and engine. If an anode is to be connected via the engine or gearbox to provide protection to the prop an electrical connection must be made between the two flanges. This can conveniently be done with tinned copper earthing braid.
If you follow the link given earlier and look at the R&D installation instructions you will see that they can provide a silver impregnated rubber tape which can be used sandwiched in the centre of the unit between the fail-safe straps. This is fine to do during the installation but perhaps not as a retrofit to an already installed coupling as basically you would have to uncouple it to fit the rubber tape.
Not wanting to mess around with the coupling, I've bitten the bullet and bought a MGDUFF EE1, found one online for £57 +vat. Cheapest I could find, they had listed the price incorrectly but honoured the price. I'll have to make a bracket to hold fix the holding post that comes with it.

